To find version of OpenSuse, run
server3:~ # cat /etc/*release NAME="openSUSE Leap" VERSION="15.1" ID="opensuse-leap" ID_LIKE="suse opensuse" VERSION_ID="15.1" PRETTY_NAME="openSUSE Leap 15.1" ANSI_COLOR="0;32" CPE_NAME="cpe:/o:opensuse:leap:15.1" BUG_REPORT_URL="https://bugs.opensuse.org" HOME_URL="https://www.opensuse.org/" server3:~ #
To install a program, run
zypper insall PROGRAM_NAME
Example
zypper install nginx